31 August 2004

Gaston submerges Richmond, Hermine makes landfall as a late summer night zephyr, and Frances stronger, faster (again)...

From Jonathan Vigh: 
 
Tropical Depression Gaston, already a prolific rain producer, went out with
a bang last evening. As the storm ciruculation slowly pinwheeled across
southeast Virginia, a massive convective blowup developed on the
circulation's northwest side. The resulting cloudburst dropped up to 4.5" of
rain in an hour over and near downtown Richmond, VA. A total of 5-12" fell
in just several hours across the city. The resulting flood turned downtown
Richmond into a raging, muddy rapids. Hundreds of cars floated away and a
20-block district of the city was submerged. Unfortunately, at least 5
people were killed. As the system moved on, a ship in the Chesapeake Bay
reported tropical storm force winds and the system was upgraded back to a
tropical storm. 

Meanwhile, the detached low level circulation of Hermine was racing
northward toward Massachussetts. Hermine made landfall at about 2 AM this
morning, bringing only some 20-25 kt southerly breezes into the area and
some thunderstorms. This was a much less significant event than the cold
front and storms which had drenched parts of New York and Vermont earlier. 

This afternoon, Tropical Storm Gaston moved passed Nantucket. It's
circulation is much more substantial than Hermine, but the storm is mainly a
marine interest. Most of the rain has finally ended across New England and
Gaston is headed for Nova Scotia and beyond, and will likely soon become
extratropical. 

Hurricane Frances passed just 145 miles of San Juan, Puerto Rico this
afternoon. The storm passed the Leeward Islands overnight, but there were
few if any reports of tropical storm force winds. Saint Thomas reported a
gust to 32 kt as the outer rainbands passed by, and Puerto Rico is
experiencing similar conditions. The latest recon aircraft reported an
spectacular stadium effect in Frances' 26 nm diameter eye and an
extrapolated a central pressure of 938 mb. The eye is getting warmer with
time, a sign that usually points to more strengthening, or at the very
least, a mature hurricane. Frances underwent at least one eyewall cycle in
the last day, and overnight, the inner eye disintegrated, leaving the
current eye which has since contracted from 35 nm to 26 nm. The appearance
on satellite imagery is nothing short of awesome. Mesovortices have been
seen whipping around in the lower part of the eye. Frances looks a lot like
Isabel in some regards, but is not as strong . . . yet. For comparison, here
is a list of the Atlantic hurricanes over the past 5 years which reached a
peak intensity equal to or higher than Frances' current intensity (this is
in no way exhaustive or even guaranteed to be accurate):

2004 Frances(so far) 120 kt 938 mb
2004  Charley  125 kt 941 mb
------------------------------------------   
2003  Isabel  145 kt 915 mb (est.)
2003 Fabian  125 kt 939 mb
------------------------------------------
2002 Lili  120 kt 940 mb
------------------------------------------
2001  Michelle 120 kt 934 mb
2001 Iris  125 kt 948 mb
------------------------------------------
2000 Keith  120 kt 941 mb
2000  Isaac  120 kt 943 mb
------------------------------------------
1999 Lenny  130 kt 933 mb
1999 Gert  130 kt 930 mb
1999  Floyd  135 kt 921 mb
1999 Cindy  125 kt 942 mb
1999 Bret  125 kt 944 mb

In summary, over 5 seasons (not counting 2004), there were 12 hurricanes
that were at least as strong as Frances (this is well above the long-term
average), an average of more than 2 per year. Only 4 storms reached 130 kt
and above -- storms this strong are pretty rare. Frances may reach this
level in the next day or two, as there are few negative factors to prevent
further strengthening. An upper low is spinning to the west over the Bahamas
-- this could crimp Frances outflow and even shear the system in a couple
days. It is more likely that Frances will nudge this system and interact a
bit, but probably not enough to cause substantial weakening. Frances'
strongest inhibition to further intensification might be internal dynamics
(eyewall cycles), but the storm is just as likely to strengthen as weaken in
that regard. Regardless of the exact strength, a severe hurricane is headed
towards the U.S. East Coast and is not likely to weaken to anything less
than a major hurricane. Potential landfall could be as soon as 4 days from
now (Saturday) or possibly as late as Sunday or early Monday. It is still
not possible to pinpoint the landfall location (or even the state of
landfall!), but the general risk area stretches all the way from Key West to
Cape Hattaras. Right now, the middle of that area, stretching from West Palm
Beach, FL to Brunswick, GA, probably has the highest chance of seeing the
major effects from Frances. Parts of the Bahamas will likely be hit
beforehand, and are currently under Hurricane Watches and Warnings.    

At 21Z, Frances was at 20.5N 65.9W and moving a little faster towards the
west at 15 kt with maximum sustained winds of 120 kt. 


Please visit my tropical Atlantic headquarters.

30 August 2004

Gaston rains itself out, Hermine may brush Massachusetts, Frances getting stronger, faster...

From Jonathan Vigh: 
 
Tropical Depression Gaston continued to rain itself out today over North
Carolina and southern Virginia. Over the last 24 hours, 2-5" of rain has
fallen over central North Carolina and southeastern Virginia. Wind gusts
up to 45 mph were reported near the NC/SC border. Gaston will continue
its plodding trek through Eastern Virginia and the Del Marva peninsula
and gradually lose its identity as it tangles with an approaching cold
front. An alternate scenario is that Gaston moves out over open (but
cold) waters and attempts a come-back, perhaps as an extratropical
entity. 

Tropical Storm Hermine lost its head and is running towards
Massachusetts. Vertical wind shear at midlevels separated Hermine's low
level center from the deep convection this morning. The system is still
at tropical storm strength, however, and may brush southeast
Massachusetts overnight. Therefore, the National Hurricane Center has
issued a tropical storm warning for this area. 

At 21Z, Hermine was at 38.4N 71.3W, or 210 miles south-southwest of
Nantucket, Massachusetts, moving north at 18 kt. Winds are at 45 kt and
the estimated central pressure is 1008 mb.

With Gaston and Hermine soon to be gone, all eyes turn towards Hurricane
Frances. The storm fought through mild southerly wind shear yesterday,
but now appears to be under little if any vertical wind shear. Frances
has a healthy appearance in the satellite imagery this afternoon: the
outflow is good in all directions and expanding in time, a sign that the
environment is favorable for intensification. Indeed, at 18Z, recon
aircraft found that the pressure had fallen to 948 mb (down from as high
as 958 mb overnight). The aircraft also found a an 18 nm inner eye with
an outer eyewall 48 nm in diameter.  Frances appears to be nearing the
end of another eyewall cycle today, and the storm will probably
strengthen as the outer eyewall contracts. At this point, there do not
appear to be any factors that would cause substantial weakening of
Frances, so the official forecast calls for a dangerous 120 kt storm in
five days. 

Frances will pass north of the Lesser Antilles overnight. Sustained
tropical storm force winds are likely in this area, and there is a
possibility that the northernmost islands (Anguilla, Virgin Gorda) could
experience hurricane conditions. Tropical storm warnings are in effect
for the northern U.S. and British Virgin Islands, Culebra, Vieques, and
Puerto Rico. If the storm stays on track, tropical storm force winds
should remain close to or offshore of northeast Puerto Rico. The Bahamas
will likely be the first to feel Frances' full fury. A strong ridge is
forecast to continue to steer Frances on a west-northwest course towards
the southeast U.S. Coast, possibly making a landfall as early as
Saturday morning. At this point in time, there does not appear to be any
trough that could recurve the storm before landfall. If the ridge
weakens towards the end of the week, Frances could travel further north
and hit North Florida, Georgia, or even South Carolina by Sunday or
Monday. Alternatively, if the ridge strengthens, Frances could make a
quick left turn into South or Central Florida by Saturday morning. Since
any potential landfall is at least 5 days away, there is still much
uncertainty -- the storm could even miss the U.S. entirely, although the
chance of that happening seems to be decreasing with time. Residents in
these areas should closely monitor Frances progress this week and
remember that 4 and 5 days forecasts typically have track errors of a
couple hundred miles.

At 21Z, Frances was at 19.5N  60.0W, with maximum sustained winds of 110
kt. She has also increased her forward motion, moving westward at 13
kt.  


Please visit my tropical Atlantic headquarters.

29 August 2004

Gaston hits South Carolina, Frances weakens slightly, and Hermine forms...

From Jonathan Vigh: 
 
In an amazing show of fury and action, the tropical atmosphere has certainly
been living up to its full potential over the last 24 hours. Since
yesterday's update, Hurricane Frances strengthened into a rare cat. 4
hurricane and has since weakened slightly, Tropical Storm Gaston
strengthened and wallopped the South Carolina coast just shy of hurricane
strength, and Tropical Storm Hermine formed from that disturbed area of
weather southwest  of Bermuda that was mentioned 2 days ago (but not
yesterday). Just to recap the records being set -- Hermine is now the EIGHTH
tropical storm to form in August, the first time that has ever happened in
the modern era (beating out 1995's 7 tropical storms). In the last 29 days,
there has been nearly as much activity as would be expected in an entire
normal hurricane season. 

First, the low-down on Gaston. This system had a short, but active life,
having been just upgraded to a tropical storm yesterday morning. Very low
vertical shear and sea surface temperatures to 28 deg C provided favorable
conditions for strengthening. Gaston was clearly on the upswing as it
approached South Carolina and made landfall near McClenanville at 14Z (near
where Hurricane Hugo made landfall in 1989). If it had had a few more hours
over water, it most likely would have become a hurricane. Gaston's
circulation (eyewall?) raked far western Charleston County and Berkley
County with high winds and heavy rains. Some beach erosion was reported
along the coast, as well as peak gusts to 82 mph in downtown Charleston and
81 mph at Isle of Palms. Trees were downed and other minor damage was
reported (preliminary), but the main problems, as expected, came from the
extremely heavy rains. Radar indicates that as much as 13-15" may have
fallen in some areas, and considerable flash flooding was occurring this
afternoon. As of 03Z, Gaston has weakened to a tropical depression, but is
continuing to drop very heavy rains as its impressive rain shield moves
northward through North Carolina. Heavy rains will continue as the remnants
of Gaston track up the Eastern Seaboard over the next couple days.

Hermine appeared on the scene today from that area of disturbed weather
south of Bermuda that was mentioned a couple days ago. Deep convection has
persisted with this storm, although the system is under some moderate
vertical wind shear. Hermine is currently at 33.2N 71.3W with an estimated
central pressure of 1005 mb. The system is moving towards the NNW at 13 kt,
and should continue northward over the next couple of days with only slight
strenghthening forecast. The remants of Gaston, a cold front, and Hermine
may mix together to make for some stormy, wet weather for New England by
Tuesday. 

Finally, onto Frances. Yesterday, Frances presented a spectacular eye which
fulfilled every expectation of a major hurricane. With the impressive
appearance, the storm was upgraded to the somewhat rare status of cat. 4,
with winds of 115 kt. Overnight and today, the storm has looked somewhat
less impressive at times. It seems that Frances has felt some southerly to
southwesterly vertical wind shear. The first aircraft flew into the storm
this afternoon and evening and verified that the storm weakend slightly this
afternoon, to 110 kts (the upper end of cat. 3) and 954 mb (the pressure was
949 mb when the aircraft first arrived in the storm). With sea surface
temperatures as warm as 29.5 deg C and a strong ridge building to the north,
Frances could strengthen again, assuming that the wind shear is low enough
to be a nonfactor. The official forecast is for Frances to remain a strong
cat. 3 hurricane through the next five days. The track forecast is more
problematic than the intensity forecast at the moment. Frances is now moving
slowly westward at 7 kt. The storm size has increased over the last couple
days, and with a track just north of due west, the storm is forecast to pass
close enough to the northernmost Leeward Islands to bring some ill effects
including tropical storm conditions. Thus, Tropical Storm Watches have been
issued for Antigua, Barbuda, St. Maartan, Anguilla, Nevis, St. Kitts, St.
Eustatius, and Saba. These are generally the northern islands of the U.S.
and British Virgin Islands and Anguilla. With the inherent uncertainty of
forecasting, a more threatening southward track cannot be ruled out at this
time. Therefore, Hurricane Watches have also been issued for the British and
Northern U.S. Virgin Islands including St. Thomas, St. John and environs,
and the islands of Culebra and Vieques.        

Some of these islands took a beating several times during the past decade.
To briefly summarize this area's recent hurricane history: in 1995, Luis hit
Barbuda and St. Martin as a cat. 4 hurricane and later in the season,
Marilyn caused tremendous damage to the St. Thomas (U.S. Virgin Islands).
Hurricane Georges raked pretty much the entire area, including Puerto Rico,
and caused large loss of life in the Dominican Republic in 1998. And in
1999, 'wrong-way Lenny' caused more trouble late in the season. 

In the longer time frame, the storm is expected to move west northwest and
menace the Bahamas. A general threat now exists to the U.S. East Coast, but
it is still too far in advance to even say which state(s) may be threatened.
If the WNW track develops, the threat to South Florida may be reduced (and
increased for areas further north), but it is too early to say. All
residents of Florida, Georgia, South Carolins, and North Carolina should
monitor and track the progress of Frances through the week.

At 03Z, Frances was near 18.9N 56.2W, moving west at 7 kt, with maximum
sustained winds to 110 kt and aircraft-measured central pressure of 954 mb.


Please visit my tropical Atlantic headquarters.

28 August 2004

Frances strengthening slowly, TD 7 becomes Tropical Storm Gaston...

From Jonathan Vigh: 
 
The depression that formed yesterday off the South Carolina coast has become
much better organized in the past day and is upgraded to Tropical Storm
Gaston, the 7th named storm of August (a tie with 1995 for the most storms
to ever form in August). The storm is drifing slowly westward and forecast
to make landfall in South Caroline in 24-36 hours. Tropical Storm Warnings
are now in effect from the Savannah Rive to Little River Inlet, and watches
are in effect for areas on either side of the warning area. A reconnaissance
aircraft is currently flying the storm and has found that Gaston is a
healthy tropical system with a central pressure of 996 mb. The storm is in
an environment favorable for strengthening, so it will likely continue to
intensify until landfall. A ridge to its northeast should prevent it from
making a quick escape out into the Atlantic. Although the storm probably has
at least a one in four chance of making it to hurricane strenth, the primary
threat from this system is still the heavy rainfall that it will be
producing over the next several days. 

At 18Z, Gaston was at 31.3N 78.7W with winds estimated at 40 mph, but
possibly climbing. 

Meanwhile, Hurricane Frances has been keeping things interesting over the
mid-Atlantic. Frances has strengthened only slightly since yesterday, to 105
kts. Overnight, the storm completed an eyewall cycle, which often happens in
intense hurricanes. Although eyewall replacement cycles are not completely
understood, basically, outer rainbands form a second outer eyewall which
then contracts and chokes off the inner eyewall. This process temporarily
halts intensification and can cause a brief weakening. An added side effect
is that the storms size can be increased to some extent. Once the inner eye
has died, the storm continues strengthening and the new eyewall can shrink
in size -- sometimes this cycle occurs multiple times over a storms
lifetime. Some more internal fluctuations are expected as Frances continues
moving towards the northwest. The vertical shear is still low and the sea
surface temperatures are still getting warmer, so Frances is forecast to
strengthen into a cat. 4 hurricane. The area of vertical wind shear
mentioned yesterday is still present, but seems to be decreasing with time.
By the time Frances reaches it tomorrow and Monday, it could be nothing more
than a speed bump to the storm. 

Maybe even more interesting than the intensity is the storm's forecast
track. A strong ridge should force the storm to make a turn to the left
starting tomorrow. The storm is already slowing down, so this may be an
indication that it is getting ready to make the turn. The official forecast
still calls for Frances to pass well to the north of Puerto Rico, the Virgin
Islands, and the Dominican Republic, but if the ridge is stronger, the turn
could occur sooner and the storm could come uncomfortably close to those
locations. This is still a distinct possibility (about a 1 in 10 chance), so
people in those locations should monitor Frances closely over the next
couple days. After that, Frances is forecast to continue west northwest
towards the Turks and Caicos islands, which may eventually feel the wrath of
Frances starting next Wednesday and Thursday. If the strong ridge continues
to hold, the storm could eventually threaten the United States. A potential
landfall is nearly a week away, and there are still many factors that could
prevent Frances from ever threatening the U.S. Nevertheless, if you live in
those locations, it doesn't hurt to review your hurricane plan and resupply
your disaster kit.      

At 15Z, Frances was located at 17.4N  51.9W and moving NW at 8 kts. Maximum
sustatained winds were estimated at 105 kts, with a  central pressure of 958
mb.


Please visit my tropical Atlantic headquarters.

27 August 2004

Frances intensifies into 3rd major hurricane of the season, TD7 forms off SC coast...

From Jonathan Vigh: 
 
August 2004 will go down in the history books as the first August (since
the era of reliable records) that three major hurricanes have formed in
the same month. Even more remarkable is that fact that in no modern
hurricane season has ever had three major hurricanes before September
(including the months of June and July). For all of this to happen in
just one month is pretty remarkable. Finally, on the subjects of
records, only two other Augusts have ever had 6 or more tropical storms
(1990 had 6 storms; and 1995 had 7 storms, 5 of which were hurricanes!).
This record may also be in jeopardy (see below). Thanks to Phil
Klotzbach for providing these statistics.

At 21Z today, Frances was upgraded to a category 3 hurricane with winds
estimated at 100 kts. This is a day ahead of schedule according to
yesterday's forecast. Indeed, Frances has intensified rapidly since it
was first numbered less than 3 days ago. 

To summarize, here is the intensity history of Frances:
 21Z August 24 just a tropical disturbance, numbered at 03Z
 21Z August 25 Frances becomes a named storm, 35 kts, 1005 mb
 21Z August 26 Frances becomes a hurricane, 70 kts, 983 mb
 21Z August 27 Frances obtains 'major' status, 100 kts, 962 mb

Of course, the intensity is only estimated. The storm will probably not
be investigated by reconnaissance aircraft until about midday Sunday. By
that time, Frances is forecast to be a cat. 4 hurricane. There are
several factors in favor of further strengthening (persistence -- it has
a good trend going, the warmer SSTs along its forecast track, and the
fact that its outflow is excellent and still improving), but Frances
could also come under some vertical wind shear in a couple days as it
passes through a weak trough axis. If this happens, the storm could
weaken in the intermediate time frame, then strengthen later next week.
It may never hit that shear, however, as a small upper low appears to be
pinching off to the northwest -- this may protect the storm somewhat. In
that case, the intensity could be dictated by internal storm dynamics.
Regardless, this storm will be very interesting to follow. 

Frances is presently located at 15.7N 49.8W and traveling NW at 12 kts.
All the forecast models show a left turn in a couple days, and the storm
is forecast to pass a couple hundred miles to the north of the Leeward
Islands and then continue passing the Greater Antilles at a comfortable
distance (Puerto Rico and the Dominican Republic). If the left turn is
sharper than forecast, these locations could be threatened by a very
serious storm. Anyone in these locations should watch the storm closely
over the weekend. This could be a bad time to start a long sailing trip.
For the long time frame (5 days), the storm may be starting to menace
the Turks and Caicos Islands. There is no use in speculating where
Frances might go beyond 5 days. Beyond this time frame, there are lots
of factors (in general, chaos) that almost always ruin even the most
sophisticated model forecasts. Residents of the United States can rest
in peace this weekend. 

Don't make the mistake of keeping all eyes (pun intended) on Frances --
some excitement is happening right off the South Carolina coast!
Tropical Depression 7 formed today, just 140 miles southeast of
Charleston (31.6N 78.1W). The storm apparently formed when the remnants
of a cold front received a bit of a kick from a small upper level
disturbance. Deep thunderstorms have been cycling in this area for the
past couple days and voila! a tropical depression formed. The depression
is forecast to strengthen slowly and drift westward or northward toward
the coast, making landfall as a minimal tropical storm. The main threat
from this storm will be heavy rains, especially because it is moving so
slowly. Always remember to never drive through flooded roadways -- it's
just not worth the risk.

And if that wasn't enough to keep track of, a tropical disturbance south
of Bermuda may be showing signs of organization. If it continues to
organize, it may be numbered as TD 8 in the next day or two. 

Will August break the record of 7 named storms (1995)? Where will
Frances go? Can she reach the elusive cat. 5 status? Stay tuned . . .
Please visit my tropical Atlantic headquarters.

August Statistics

From Phil Klotzbach:

With the naming of Francis, we have now had six named storms form in August.  Only two other years since 1950 have had the same or more named storms than this... 1990 also had six named storms form, and 1995 had seven named storms form.
We have now had four hurricanes form in August... 1976 and 1950 also had four hurricanes form in August, while 1995 had five hurricanes form.

If Francis goes intense (which it looks pretty likely to do), we will have had three intense hurricanes form in August.  That hasn't been observed in the modern record (since 1950).
NTC for August currently stands at 55.  If Frances goes intense, our NTC will be in the 60s.  NTC has only cracked 60 in August five other times since 1950.  1996 - 61, 1958 - 63, 1950 - 69, 1995 -71,  1955 - 82.

Please visit my tropical Atlantic headquarters.

26 August 2004

Frances rapidly becomes a hurricane...

At 21Z today, Frances was upgraded to a hurricane, the 4th of the
season, based on satellite appearance.  The CDO is growing and
maintaining cloud top temperatures around -75C.  I suspect that
microwave imagery will soon reveal an eye/eyewall forming under the
CDO.  The 21Z position is 13.7N 46.4W and heading WNW at 14kts. 
Intensity has jumped to 70kts and 983mb (35kts and 22mb stronger than 24
hours ago!).

The forecast is for significant intensification, reaching CAT2 status by
Friday morning and CAT3 status by Saturday morning.  If it achieves CAT3
anytime by the end of the month, a new record will be set in the
Atlantic... never has there been an August with 3 major hurricanes.  The
future track is still tricky, because it will be slowing down.  In 5
days, it should be just north of the Lesser Antilles, so interests on
shore (Bahamas, Bermda, or US) will certainly have a peaceful weekend
and first half of next week at least.

Elsewhere, there's little of interest to mention.  There's a weak
tropical wave near the Cape Verde Islands, and another one exiting the
African coast right now.

You'll find the most current satellite imagery, track forecast,
advisories, and more at http://mcwar.org/tropics/

I will be out of town until Sept 6, but Jonathan Vigh will be filling in
for me.  Jonathan is a graduate student at CSU Atmospheric Science in
the same Tropical Dynamics research group that I'm a part of and is very
knowledgeable on the subject.


Please visit my tropical Atlantic headquarters.

25 August 2004

Frances forms from tropical wave...

At 03Z this morning (11pm EDT last night), NHC upgraded the strong
tropical wave in the central Atlantic to TD6.  Then at 21Z today, it was
upgraded to Tropical Storm Frances, based on an improving satellite
presentation (CDO and banding).  It presently is located at 11.6N 40.5W
and tracking W at 15kts.  Intensity is estimated to be 35kts and 1005mb.

Frances is forecast to slow down, and gradually strengthen too.  Models
indicate that it will begin to move NW as a weakness in the subtropical
ridge develops.  Then by early next week, the ridge should rebuild and
the track would turn more westerly again.  This sort of stair-step
pattern is similar to what Andrew '92, Floyd '99, and Isabel '03 did. 
However, east coast residents don't need to start hanging storm shutters
just yet... it's well over a week until that would be an issue, if at
all.

The large wave over western Africa that looked impressive yesterday is
not looking as robust now.  It's at about 12N 28W.


Please visit my tropical Atlantic headquarters.

24 August 2004

Strong tropical wave exits Africa...

First, to wrap up previous activity, the final advisory was written on
Danielle on 21 Aug at 15Z.  It is still a low-level swirl in the open
ocean west of the Azores and shows no signs of coming back.  Ending
chronologically with Danielle (or alphabetically with Earl), the season
stands at 21.75 Named Storm Days, 9.75 Hurricane Days, and 1.00 Intense
Hurricane Days.

The main story is a strong wave that exited Africa on Friday afternoon
and is now at about 12N 35W, tracking westward at a healthy 13kts. 
Conditions are favorable for development, it will likely be upgraded to
TD6 in the next 6-12 hours.  The next name on deck is Frances.

Looking ahead, there's a huge mid-level circulation with associated
convection still over western Africa (~12W).  This will be interesting
to watch as it enters the eastern Atlantic in a day or two.  We are now
in the prime of the "Cape Verde Season", so these waves that exit the
African coast near the Cape Verde Islands climatologically stand a
decent chance of making it to a named storm.


Please visit my tropical Atlantic headquarters.

20 August 2004

2004 Fun Hurricane Facts

From Phil Klotzbach:

We had four named storms form in six days in 2004 (8/9-8/14) - Bonnie, Charley, Danielle, and Earl.  The last time this happened was in 2002: Isidore and Josephine on 9/18 and Kyle and Lili on 9/23.  The last time this happened in August was in 1999:  Bret - 8/19, Cindy - 8/20, Dennis and Emily - 8/24.   In 1980, four named storms formed in three days!  Danielle and Earl on 9/5, Frances on 9/6, and Georges on 9/7.  Interestingly enough, though, we have not had more than four storms form in any six day period since 1950.

The NTC for August 2004 is now up to 49.  That puts us in 9th place for NTC in August since 1950.  As of the 15Z advisory on Danielle, August 2004 has seen 21.75 named storm days which puts us in an 8th place tie with 1996.

Another interesting tidbit... August 2004 has witnessed the formation of two intense hurricanes (Alex and Charley).  Since 1950, no more than two intense hurricanes have developed during the month of August.  So, if we can get one more IH before the end of August, we'll be in record territory! 

Please visit my tropical Atlantic headquarters.

18 August 2004

Danielle dwindling...

Very strong vertical shear has ripped Danielle apart, and is now
struggling to maintain Tropical Storm intensity.  The low-level center
is completely exposed, and what convection there is is being whipped off
to the north.  As of 21Z, TS Danielle was located at 29.3N 38.4W and
tracking NNE at 9kts.  Intensity is 45kts and 1005mb.  Further rapid
weakening is imminent, so I suspect we will see the end of this one
tomorrow.

Elsewhere, there are a couple of tropical waves between Africa and the
Lesser Antilles, at about 30W and 50W.  Both show minimal signs of
organization, but will still be monitored.


Please visit my tropical Atlantic headquarters.

17 August 2004

Danielle STILL a Category 2 storm...

For nearly 2.5 days, Danielle has maintained CAT2 intensity over the far
open ocean.  However, a rapid demise is in store as a strong upper-Low
spins just to its west and imposes very strong vertical wind shear over
the hurricane.  
http://www.nrlmry.navy.mil/archdat/atlantic/tropics/vapor/LATEST.jpg
At 21Z, Hurricane Danielle was located at 25.8N 40.5W and tracking N at
16kts.  The intensity has decreased a bit to 85kts and 974mb.  Weakening
should continue rather quickly, and is expected to cross over the Azores
midday Saturday as a Tropical Storm.

The remnants of Earl are looking worse as time goes on, and regeneration
seems more and more unlikely, much to the relief of Gulf coast
residents!  The open wave is now located near the east coast of
Nicaragua, in the far southwestern Caribbean Sea.  It does stand a shot
at regeneration in the eastern Pacific basin.

Still tracking the tropical wave near the Cape Verde Islands, it's now
at approx 10N 30W and heading W at 20kts.  It's not very well organized
presently, but will be watched as it heads across the deep tropics
toward the Lesser Antilles.

As of 21Z today, the Atlantic basin is at 48% of the average activity
for the entire season, and that has all occured since August 1!


Please visit my tropical Atlantic headquarters.

16 August 2004

Earl weakens, Danielle heading out...

At 15Z today, the NHC downgraded TS Earl to an open wave, based on an aircraft being unable to find a closed surface circulation.  This is largely due to the fast forward motion.  The axis of the wave is at approx 75W.  It's likely that Earl will regenerate in the western Caribbean in a couple days, and head toward to the Yucatan.  This system will be very closely monitored.

Hurricane Danielle continues to spin out in the open Atlantic, already beginning to recurve at 40W.  As of 21Z today, the storm was located at 19.7N 38.6W and heading NNW at 16kts.  Intensity is still 90kts and 970mb, holding steady as a CAT 2 hurricane.  Conditions will begin to deteriorate though, and Danielle is forecast to be a TS by Thursday. Despite the slightly increasing SSTs in its forecast track, the shear will soon increase to 40kts!

Elsewhere, there's a tropical wave at about 10N 25W, just south of the Cape Verde Islands.  It's tracking westward at 20kts and could become TD6 in a day or two.  There is ~15kts of easterly wind shear here, and the SST is 28C and increasing to the west.

Please visit my tropical Atlantic headquarters.

15 August 2004

Charley finally out of the picture, Danielle a hurricane, Earl crossing the Windwards...

Since yesterday's update, Charley has done little more than make rain
over the northeast, and is presently over Nova Scotia.  The NHC has
ceased writing advisories on the storm because it has merged with the
mid-latitude trough.  There are still over 1 million people without
power in FL, and the death toll has reached 16, and could still climb a
bit more.  The scene in the Charlotte Harbor area is one of total
destruction, particularly the town of Punta Gorda, just 20 miles NNW of
Fort Myers.

At 03Z today, Danielle was upgraded to the third hurricane of the season
based on satellite appearance.  It now has a clear eye and vigorous
eyewall, symmetric outflow, and spiral bands.   Further strengthening is
likely through Wednesday when a trough digs into the area and introduces
vertical shear.  Danielle is currently a CAT1 storm, but could reach
CAT2 and even CAT3 before conditions deteriorate.  As of 15Z, Hurricane
Danielle was located at 15.0N 32.7W and moving WNW at 14kts. 
Satellite-estimated intensity is 75kts and 981mb.  It will not pose a
threat to land, as it will recurve to the northeast by 45W.

Earl continues to intensify.  It crossed the Windward Islands this
morning as a Tropical Storm, and is still at 40kts and 1009mb.  Although
not very strong now, environmental conditions are favorable (and slowly
improving),  so it is expected to become the 4th hurricane of the season
by the middle of this week.  It's presently at 11.9N 62.0W and tracking
W at a whopping 24kts.   The forecast track takes it near Jamaica on
Tuesday morning, and through the Yucatan Channel on Thursday morning. 
As I mentioned yesterday, all Gulf residents should be watching Earl
very closely this week, as it could be a major player next weekend. 
Landfall looks likely as a major hurricane somewhere in the central Gulf
coast area (take that very generally, since it's still 7 days out!).

Up to and including the 15Z advisory today, this season (which has only
been active for TWO WEEKS!!) has seen:
- 5 Named Storms
- 15.25 Named Storm Days
- 3 Hurricanes
- 7.00 Hurricane Days
- 2 Intense Hurricanes
- 1.00 Intense Hurricane Days
In terms of a seasonal net tropical cyclone activity number (those six
parameters compared to an "average" year), we have reached 45% of the
6-month seasonal average in just 2 weeks.  Of course, the hurricane
seaosn technically began on June 1, but the first named storm didn't
occur until August 1.


Please visit my tropical Atlantic headquarters.

14 August 2004

Charley makes 3rd landfall, Danielle and Earl trekking westward...

After Charley's landfall at Charlotte Harbor yesterday afternoon, it continued inland across the FL peninsula, hitting Orlando and Daytona Beach head-on, as a CAT2 and CAT1, respectively.  Then the resilient hurricane crossed over the Gulf Stream and headed for South Carolina. The forward speed increased to the point where intensification was hindered, and it hit Myrtle Beach, SC around noon EDT today.  As of this writing, the center is 70 miles south of Norfolk, VA and heading toward it at 26kts.

Current intensity is 60kts and 1000mb, finally dropping the mighty Charley down to a Tropical Storm.  The forecast track takes it over DE, NJ, then eastern New England, as a weakening TS then TD.  NJ and eastern PA can expect the worst weather in the early morning hours on Sunday.

Yesterday, Charley was responsible for 8 reported tornadoes in FL, and another 7 today in FL and NC.  The town of Punta Gorda which sits right on Charlotte Harbor was hardest hit, and as Florida Governor Bush said, "Our worst fears have come true... it's hard to describe seeing an entire community flattened".  The death toll is 15, but that number rises every hour as more bodies are found in the rubble.  At least 2 million people in FL are without power.

TS Danielle continues to get better organized, with spiral bands and deep convection wrapping around the core.  As of 21Z today, the storm is located at 13.7N 28.7W and moving WNW at 13kts.  Intensity is 55kts and 994mb.  It is very close to being upgraded to a hurricane, which could happen later tonight or Sunday morning.  As of now, all guidance indicates that Danielle will not be a threat to land; recurving into the open ocean by about 45W.

At 21Z today, TD5 was upgraded to TS Earl, the 5th named storm of the season.  The 1006mb Low is at 10.8N 54.5W and heading WNW at 21kts. Maximum sustained winds are 35kts.  Earl could become the 4th hurricane on Monday (after Danielle makes the 3rd), and DOES pose a threat to land.  The forecast track is very similar to Charley's... crossing the Lesser Antilles midday Sunday, Jamaica on midday Tuesday, then western Cuba midday Thursday.

A Tropical Storm Warning has been issued for Trinidad, Tobago, and the Windward Islands.  Gulf residents should be paying very close attention to Earl as it will be a key player in the Gulf at the end of the week.

Please visit my tropical Atlantic headquarters.

13 August 2004

Charley hits FL as CAT4, TD4 continues on, and TD5 forms...

At 4pm EDT today, Hurricane Charley slammed into Charlotte Harbor as a
CAT4 storm.  It missed the projected target of Tampa by about 65 miles,
and was about 30kts stronger than expected.

Ending at 21 today, the central pressure fell:
 - 39mb in 24 hours
 - 29mb in 12 hours
 - 24mb in 6 hours
Just for reference, the world record holders for those brackets are
101mb/24h, 77mb/12h, and 43mb/6hr.  Although not at the top of those
lists, this was still one of the most rapidly intensifying hurricanes in
Atlantic history, and it did so just miles before landfall.

So far, damage reports are extensive, and have just begun to come in. 
The primary eyewall was very tiny and missed Fort Myers, but was close. 
Port Charlotte most likely sustained the heaviest damage.  Charley is
now heading across the peninsula toward Orlando then Daytona Beach,
still as a strong hurricane.  Tornadoes are possible all along the storm
track; 5 reports have already come in from Florida.

At 21Z, the hurricane was located inland at 26.9N 82.2W and tracking NNE
at 19kts.  Intensity was an incredible 120kts and 941mb.  It is forecast
to exit the FL peninsula at Daytona Beach, briefly pass over the Gulf
Stream in the Atlantic, then make a third landfall near Myrtle Beach,
SC.  Hurricane Warnings cover all of the western FL peninsula, the
northeast FL peninula, GA, SC, and NC up to Cape Fear.  A Tropical Storm
Watch is in effect from Cape Fear, NC to the Chesapeake Bay.  It will be
passing over PA/NJ in the early morning hours on Sunday, and up by Maine
midday Monday.

TD4 is still getting better organized, and is nearly a Tropical Storm. 
It's currently at 12.5N 24.0W and moving W at 13kts.  It should become
TS Danielle tonight or tomorrow morning.  It will most likely recurve
into the open Altantic long before reaching the Lesser Antilles.

At 21Z today, the strong tropical wave I mentioned this morning was
upgraded to TD5... now located at 8.9N 46.2W.  The 1009mb Low is heading
W at 17kts and is expected to continue on this track for the next
several days, passing over the Lesser Antilles Sunday afternoon, and
Jamaica on Wednesday as a strong CAT1 hurricane (basically following in
Charley's footsteps).  This could become TS Earl by tomorrow afternoon.


Please visit my tropical Atlantic headquarters.

Charley slams Cuba, Florida in sights, TD4 forms, TD5 in the making...

At 04Z today, powerful CAT2 Hurricane Charley hit Cuba just south of
Havana in the town of Batabano.  About 50,000 people were evacuated from
Cuba's threatened coastlines.  Nearly 2 million people have now been
ordered to evacuate the west-central Florida peninsula.  Electricity and
water are expected to be shut off in several areas in the Tampa Bay area
this afternoon in preparation of the strongest storm that area has seen
in 83 years.

At 15Z, Charley was at 25.2N 82.8W and moving N at 16kts.  You can see
the current position easily from the Key West radar
(http://www.wrh.noaa.gov/radar/latest/DS.p19r0/si.kbyx.shtml) and the
Tampa radar
(http://www.wrh.noaa.gov/radar/latest/DS.p19r0/si.ktbw.shtml). 
Intensity is now 95kts, or just shy of a CAT3 storm, and further
strengthening is possible before landfall.  MSLP has dropped to 965mb. 
Landfall is expected to occur around 8pm EDT this evening in the Tampa
Bay area.

Hurricane Warnings are in effect from the FL Keys up to the panhandle,
and Tropical Storm Watches and Warnings have been issued for the eastern
FL peninsula and the GA and SC coasts.  A Hurricane Watch has been added
to the northeast FL and GA coasts.  The areas right near landfall can
expect at least a 12' storm surge, plus widespread areas receiving 6-8+
inches of rain.  It is still expected to track over the eastern seaboard
states, hitting central VA on Sunday morning, eastern PA midday Sunday,
and central NY on Sunday night.  Flood Watches already extend from
southern Florida all the way up to northern Maine!

The strong tropical wave near the Cape Verde Islands has been upgraded
to TD4 at 15Z today.  The 1009mb Low was at 12.2N 22.7W and tracking W
at 12kts.  It is still very well organized (for a Depression) and could
become TS Danielle later today.  Note how far east this is... not even
at the Cape Verde Islands yet!  Still, Alberto 2000 had this beat when
it became a Depression at 18W.

Elsewhere, there's a healthy tropical wave out near 10N 45W.  It's
moving W at 10kts and has a 1013mb Low embedded within it.  It has shown
continued signs of organization and could become TD5 later today or
tomorrow.

As an aside, the remnants of Bonnie were responsible for 23 tornado
reports in FL, SC, and NC yesterday.  It is not uncommon at all for
landfalling tropical cyclones to spawn tornadoes.  This threat will
certainly exist in Charley all along its path.


Please visit my tropical Atlantic headquarters.

12 August 2004

quick Charley update

The latest intensity as of 18Z is 90kts, or a CAT2 hurricane.  Charley
is still intensifying quickly with nearly ideal environmental
conditions.  If this does hit the Tampa and St. Petersburg area as a
major hurricane, it will be their first in 83 years.

Mandatory evacuations have now displaced at least 500,000 people in west
central and southern FL in preparation of Charley's landfall tomorrow. 
(Already, traffic on Hwy 1 out of the Keys has been gridlocked due to
accidents.)  Cuba has evacuated over 26,000 people to inland locations
so far.


Please visit my tropical Atlantic headquarters.

Bonnie hits Florida as TS, Charley still intensifying...

Wind shear has kept Bonnie from becoming a hurricane, and it made
landfall near Apalachicola, FL today at noon eastern time as a tropical
storm.  A Tropical Storm Warning is still in effect for much of the FL
panhandle.

At 15Z today, TS Bonnie was located at 29.5N 85.2W and moving NE at
24kts.  Intensity was 45kts and 1002mb.  It will continue on a NE track
and pass over the eastern seaboard states, from GA up to NY, passing
over central VA on Friday morning, eastern PA midday Friday, and eastern
NY Friday evening.  Although it will be making the extratropical
transition shortly, it will still be potent system and has the potential
to drop heavy rain along its entire track.

Charley skimmed by Jamaica yesterday, and passed between the Cayman
Islands this morning, and around that time, developed an eye.  Actually,
the eye was first seen in microwave imagery about 24 hours ago, but it
only became a cloud-top feature in the VIS and IR this morning.  It is
approaching western Cuba, and will be passing over VERY high heat
content (combination of ocean depth and temperature).

As of 15Z, the strong CAT1 hurricane was at 19.7N 81.2W and tracking NW
at 15kts.  Aircraft-measured intensity was 80kts and 983mb.  Since that
fix, the storm has visually gotten much better organized, and is most
likely a CAT2 by now.

Hurricane Warnings are on for the Cayman Islands, western Cuba, the FL
Keys, and the western FL peninsula up to Charlotte Harbor, then a
Hurricane Watch picks up there northward to about Cedar Key.  Landfall
is expected on Isla de Pinos, Cuba this evening, mainland Cuba tonight,
and the Tampa, FL area late Friday afternoon.  Given the positive
environmental factors, Charley should be taken very seriously as it
could be a major hurricane at Florida landfall... in a populated area of
the coast.  I suspect that evacuation orders should be commencing today
in the Tampa area.  You can view a detailed Evacuation Map of the likely
landfall area here:
http://www2.sptimes.com/pdfs/hurricanemaps/2004/hurr-map-hill.pdf

To make matters worse, Charley's track should be nearly identical to
Bonnie's over the eastern states.  The storm should pass over central VA
midday Saturday, eastern PA on Sunday morning, and eastern NY midday
Sunday.  Clearly this could mean MAJOR inland flooding.

http://www.spc.noaa.gov/products/wwa/ shows the current Watches and
Warnings.  Besides the obvious Hurricane Watches and Warnings spanning
most of FLorida, Flood and Flash Flood Watches extend from FL all the
way up to PA and NJ.  In addition, Tornado Watches have been issued in
FL, GA, SC, and NC.

Elsewhere, a very strong tropical wave with an embedded 1008mb Low has
just exited the African coast and tracking W at 15kts.  It already looks
quite impressive with an obvious mid-level circulation.  The Low is at
about 12N 18W.


Please visit my tropical Atlantic headquarters.

11 August 2004

The Dynamic Duo, Bonnie and Charley, take aim on Florida...

Bonnie is still small, but gradually getting stronger as it heads toward
the FL coast.  At 21Z today, TS Bonnie was at 26.7N 89.3W and heading NE
at 10kts.  Intensity is 55kts and 1001mb.  The storm is being sheared
from the west, but is also over the amply warm SSTs in the Gulf
(http://www.mcwar.org/tropics/GOES_sst/gulf.png).

A Hurricane Watch and Tropical Storm Warning are in effect for the
extreme western FL panhandle.  A Hurricane Warning is in effect for the
rest of the FL panhandle and northern parts of the western peninsula. 
Landfall is expected midday Thursday near Apalachicola as a minimal
hurricane.  Again, since Bonnie is so small, it will respond rapidly to
changes in the environment, good or bad.  This leaves the door open for
rapid intensification offshore which is particularly dangerous because
of the element of surprise.  The long-range track still takes the storm
over the eastern seaboard then up into the northeast states including
PA, NJ, and NY (it would be a weak Depression or totally dissipated by
then, but still carries the threat of inland flooding, a la Agnes '72 -
http://weather.unisys.com/hurricane/atlantic/1972/AGNES/track.gif).

Charley has continued to organize as it moves quickly across the
Caribbean.  Early this morning, aircraft recon found a closed eyewall,
and a few hours later at 18Z, was upgraded to Hurricane Charley, the
second of the season.  The satellite presentation is very impressive,
now sporting a ragged eye in the VIS and IR as well.  As of 21Z,
Hurricane Charley was located at 17.0N 77.5W and moving WNW at 15kts. 
Maximum sustained winds are 65kts and the minimum sea-level pressure
(MSLP) is 993mb.

A Hurricane Warning has been issued for the Cayman Islands and Jamaica. 
A Hurricane Watch is in effect for western Cuba, the Florida Keys, and
the southern portions of the western FL peninsula up to Fort Myers.  The
eye will pass very near Jamaica this afternoon, and could temporarily
weaken it as it interacts with the mountainous terrain there.  However,
the longer-range forecast is for continued strengthening, and recurving
in the Gulf, heading for the FL peninsula, somewhere in the Fort Myers
to Tampa area midday Friday.  After that, the track may follow closely
in Bonnie's footprints, riding northward along the eastern seaboard and
into the northeast states.  If this scenario verifies, states from FL to
NY could be looking ahead to very significant flooding by then end of
the weekend.

IF Bonnie reaches hurricane strength, that would make the first three
named storms all hurricanes as well.  The last time that happened was in
1992 (Andrew, Bonnie, and Charley, coincidentally).  There was a
Subtropical Storm before Andrew though, and although not named then, it
would be now based on changed naming conventions.  The last time without
exception was 1983 with Alicia, Barry, and Chantal.


Please visit my tropical Atlantic headquarters.

10 August 2004

Bonnie and Charlie intensifying...

At 21Z yesterday, the remnants of TD2 were upgraded to TS Bonnie, based
on aircraft recon.  It's a very tight circulation, but headed for the US
coast.  It's in moderate shear, but over very warm SSTs; given the small
size of the storm, it will respond readily to any positive or negative
influences.  The 21Z advisory today places TS Bonnie at 24.7N 90.5W and
tracking N at 5kts.  Intensity is 45kts and 1004mb.  It is expected to
continue on the northward track, the recurve toward the Florida
panhandle.  Hurricane intensity should be reached by Wednesday evening
(the NHC forecast calls for a 70kt hurricane making landfall near
Apalachicola on Thursday morning).

After landfall, the track may take the weakening system inland over the
eastern seaboard states, including over DE, NJ, PA, and NY.  If this
occurs, heavy flooding would be a concern.

Also, at 09Z this morning, TD3 was upgraded to TS Charlie, the third
named storm of the season.  As fo 21Z, TS Charlie was at 15.2N 70.8W and
racing WNW at 23kts.  Maximum sustained winds have increased to 45kts
and the MSLP is down to 999mb.  It is forecast to become an 85kt
hurricane by landfall on Saturday.

A Tropical Storm Warning is in effect for souther Haiti and all of
Jamaica.  A Tropical Storm Watch is in effect for the Cayman Islands. 
These could be upgraded to Hurricane Watches & Warnings if Charlie
continues to intensify.  As far as the longer-range track forecast goes,
the FL panhandle and western FL peninsula should be prepared for this
one too.  The impact of two consecutive landfalling hurricanes on the
same location could be huge.


Please visit my tropical Atlantic headquarters.

09 August 2004

No named storms, yet...

The remnants of TD2 have traversed the hostile Caribbean Sea, recently
passed through the Yucatan Channel, and now entering the Gulf of Mexico
(23N 88W). It is taking advantage of the improving environmental
conditions and shows signs of re-development after its 5-day hiatus. 
There's weak northerly wind shear through the entire Gulf, and SSTs are
29+ C.  An aircraft recon flight into the system later today will give a
better idea of the pressure and wind structure.  The eastern Gulf coast
should be watching this very closely... there is a chance for landfall
from the FL panhandle westward to LA, and possibly as a hurricane.

There is a very vigorous tropical wave over the Windward Islands (around
12N 61W).  This is the same wave I mentioned in the Aug 6 update when it
was out at 40W.  It exited Africa on August 2, and has gradually become
more organized, and could be upgraded to TD3 or even TS Bonnie later
today.  It is tracking west at 20kts.

Lastly, there's a disorganized wave just west of the Cape Verde Islands,
at about 10N 30W, but some of the computer models cling onto it and
develop it.


Please visit my tropical Atlantic headquarters.

06 August 2004

The end of Alex...

At 15Z today, the NHC issued the final advisory on Alex.  It has become
an extratropical cyclone over the far north central Atlantic.  The final
intensity estimate was 50kts and 987mb, located at 47.5N 34.6W and
zipping off to the ENE at 40kts.  In the end, Alex accumuluated 5.25
Named Storm Days, 3.25 Hurricane Days, and 0.75 Intense Hurricane Days.

The remnants of TD2 have still not vanished from discussion.  Although
under horribly high vertical shear now, it looks like conditions will
improve during the weekend, possibly allowing this stubborn wave to make
a comeback.  IF it does, next week could become very interesting in the
Gulf of Mexico, but don't count your waves until they hatch.  It's
presently just south of Haiti.

Elsewhere, the tiny disturbance in the central Atlantic (around 20N 49W)
still shows some signs of organization.  It has a 1013mb Low embedded in
the wave, and is tracking WNW at 15kts.  Vertical shear is rather
strong, so that could delay or hinder further organization.

Finally, there's a very impressive wave at about 10N 40W.  Conditions
are presently favorable, and should remain that way.  It will be
monitored very closely over the next few days for development into a
Depression.


Please visit my tropical Atlantic headquarters.

05 August 2004

Alex becomes first major hurricane of the season...

At 03Z today, Alex was upgraded to 105kts, making it the first major
hurricane (CAT3+) of the season.  Although Alberto 2000 was also the
first Depression, Tropical Storm, Hurricane, and Major Hurricane that
year, Alex has earned a spot in the record books.  It is the strongest
hurricane ever at such a high latitude in the Atlantic.

As of midday Thursday, Alex has crossed north of the Gulf Stream, so
intensity will begin to drop off quickly.  The storm's future is dismal,
and will transition to an extratropical cyclone by Friday evening,
finally getting absorbed into the vigorous north Atlantic storm track
over the weekend.  Intensity was lowered to 90kts and 970mb at 21Z.  It
is now located at 43.6N 52.8W and racing ENE at 39kts.

The remnants of TD2 are still convectively active.  Although battling
strong westerly wind shear, former-TD2 has kept a cold CDO and
persistent convection during the night and all day today... AND has now
slowed down to about 12kts.  Once the vertical shear relaxes in the next
day or two, there's a fair chance for regeneration.  

There is also a small surface Low at about 17N 43W with an MSLP of
1015mb and tracking W at 15kts.  This came from the tropical wave that I
mentioned three days ago.  Although lacking significant convection,
conditions are marginally favorable for develoment and will be watched. 
Finally, a tropical wave has just exited Africa today and will be
monitired for development; the models do favor it!


Please visit my tropical Atlantic headquarters.

04 August 2004

Alex gains strength, TD2 falls apart...

As Hurricane Alex heads out into the open ocean, conditions become even
more ripe for intensification.  Vertical shear is virtually zero, and
the track is following the core of the Gulf Stream, so SSTs remain
plenty warm.  As such, Alex now has a textbook appearance with a warm
clear eye, symmetric cold cloud tops over the eyewall, and beautiful
whispy cirrus outflow spreading anticyclonically outward.

As of 21Z, Alex was brought back up to 90kts and 970mb (after weakening
to 75kts and 979mb this morning), and appears to still be on a
strengthening trend.  If objective satellite-based intensity estimates
continue to show what they are now, Alex should be upgraded to a CAT3
hurricane tonight (probably 100-105kts).  Current location is 37.9N
67.5W and tracking ENE at 16kts.

NHC issued the final advisory on TD2 at 21Z.  Although still sporting
healthy convection and a nice storm-relative circulation, the forward
speed of 20kts hinders finding a closed earth-relative circulation;
therefore, it is downgraded to an open wave.  The final position was
13.5N 63.5W.  I suspect however, that we have not heard the last from
TD2.  If it slows down and can survive the high-amplitude trough
expected to bring westerlies as far south as Cuba, it may regenerate in
a few days.  This scenario is not favored by the models, but the models
have been wrong before!


Please visit my tropical Atlantic headquarters.

03 August 2004

Alex moves away from coast, TD2 gets better organized...

Alex's eyewall made a brush with Cape Hatteras today, but the eye itself
never passed over.  The closest approach was at about 17Z when the
center of the eye was just 15 miles offshore.  It is now moving
northeast away from the coast, and gradually accelerating.  A Hurricane
Warning is still in effect for the Outer Banks of NC, but that will be
allowed to expire as Alex heads out.

At 21Z, CAT2 Hurricane Alex was at 35.8N 74.6W, about 65 miles northeast
of Cape Hatteras.  Intensity has changed little today, and is still at
85kts and 972mb.

TD2 continues to show signs of intensification, with healthy outflow,
banding, and deeper sustained convection.  At 21Z, the Depression was
located at 13.6N 56.6W and tracking W at 20kts.  It is still weak with
sustained winds of 25kts and a MSLP of 1009mb.  The fast forward motion
makes it harder to discern a closed surface circulation, but an aircraft
may be able to investigate the system on Wednesday.

A Tropical Storm Warning is in effect for St. Lucia in the Windward
Islands.  A Tropical Storm Watch is in effect for the Windward Islands
north of St. Lucia, and for the majority of the Leeward Islands. 

The forecast is somewhat tricky... a weakness in the ridge at about 65W
may or may not pull TD2 northward into the Atlantic.  If not, it could
keep trekking westward across the Caribbean.  In either case, it's
likely that it will increase in strength over the coming days, becoming
named on Wednesday and a hurricane on Friday (Bonnie). 

Elsewhere, the tropical wave near the Cape Verde Islands has lost a lot
of its identity and will probably not develop.


Please visit my tropical Atlantic headquarters.

Alex becomes first hurricane of the season, and TD2 forms east of Windward Islands...

Not only was Alex the first TD and TS of the season, but at 06Z this
morning, became the first hurricane.  The last time this feat was
accomplished was in 2000 by Alberto.  This is also a case of rather
efficient intensification; the central pressure fell 11mb in 12 hours
(06Z-12Z today).

As of 15Z today, Hurricane Alex was located at 34.7N 75.8W, or just 30
miles east of Morehead City.  It's moving NE at 13kts; maximum sustained
winds are 85kts and the MSLP is 973mb (this makes Alex a Category 2
hurricane!). The eye diameter is 23 miles.

The central NC coast is under a Hurricane Warning, and the northern
section of the NC coast is under a Tropical Storm Warning.  A
spectacular radar loop showing Alex just off the NC coast can be viewed
at http://weather.noaa.gov/radar/loop/DS.p19r0/si.kmhx.shtml.  Very
heavy rainbands are onshore, and the eyewall could make landfall on the
Outer Banks if the track wobbles just slightly to the left.

So far, storm surge along central NC has reached 4 feet, and seas just
offshore are 12 feet.  Radar-estimated rainfall totals near Cape Lookout
are 6", and still raining very heavily there.  The eye will come within
miles of Cape Hatteras in a few hours.

The strong tropical wave east of the Windward Islands has been upgraded
to TD2 at 15Z.  It is at 13.2N 54.2W and moving quickly W at 18kts. 
Winds are 25kts and MSLP is 1009.  The Depression is expected to
strengthen fairly rapidly, becoming a TS later today and a hurricane by
Friday morning.  The next name on deck is Bonnie.

Also, the tropical wave near the Cape Verde Islands is looking more
impressive today too.  A more complete overview of this wave will be
given later today.


Please visit my tropical Atlantic headquarters.

02 August 2004

Alex getting stronger...

TS Alex is still drifting very slowly northeastward along the SC/NC
coast, right along the core of the Gulf Stream.  Although intensity is
still 50kts and 993mb, radar and IR imagery suggest that it is getting
its act together, and will likely be at or near hurricane intensity
later tonight.

A Tropical Storm Warning is in effect for the northern half of the SC
coast up to Cape Fear, NC, and then also the extreme northern NC coast. 
A Hurricane Warning is in effect from Cape Fear to Cape Hatteras, NC.
Although the center of the storm may never quite hit land, the outer
rainbands will, and cause strong winds and very heavy rain.  You can
track the storm via radar at
http://weather.noaa.gov/radar/latest/DS.p20-r/si.kltx.shtml

The tropical wave I mentioned yesterday is getting better organized. 
It's presently at about 11N 48W and tracking W at 15kts.  It has a
1012mb Low associated with it and could be upgraded to TD2 in the next
day or two... as soon as there's a closed surface circulation with
persistent deep convection.

A new tropical wave has just exited Africa and is located at about 13N
23W.  There's also a 1012mb Low embedded within it, and is moving W at
15kts.

Both waves can easily be tracked on the following site:
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/hovmoller/

Please visit my tropical Atlantic headquarters.

Tropical Storm Alex gets better organized very close to coast...

TS Alex is just 120 miles southeast of Charleston, SC, and organizing
quickly.  Last night, Alex was seemingly rather disorganized, with the
convection all displaced to the south of the center.  This morning, in a
matter of just 2-3 hours, an eye, spiral rainbands, and ragged eyewall
have formed (first evident in the radar imagery, and more recently in
the visible satellite imagery as well).

As of 15Z, Alex was located at 31.5N 78.7W and drifting ENE at 4kts. 
Intensity measured by aircraft is 50kts and 993mb.  Given the recent
trend of improved organization, further strengthening is very likely,
and Alex might become the first hurricane of the season.

It appears that the storm will just scrape the US coast, passing very
close to Cape Fear and Cape Hatteras Tuesday morning.  A radar loop from
Charleston, SC shows the circulation and eye quite nicely:
http://weather.noaa.gov/radar/loop/DS.p20-r/si.kclx.shtml.  

Another update will be sent out later today which will give an update on
Alex, as well as the developing tropical wave in the deep tropics.


Please visit my tropical Atlantic headquarters.

01 August 2004

First named storm of the season in the Atlantic...

TD1 strengthened to Tropical Storm Alex at 21Z today based on aircraft recon into the storm.  As of 21Z, Alex was located at 31.7N 79.2W (only 90 miles off the coast near Charleston, SC) and was nearly stationary. Intensity was measured by the plane to be 35kts and 1010mb.  In the near future, TS Alex is expected to strengthen slightly to 45kts and to begin moving north then northeast.

Infrared satellite imagery shows a large CDO with -75C cloud tops indicating persistent deep convection near the center of circulation. Stronger shear and subsidence on the US side of the storm should keep the storm from intensifying too rapidly, despite sitting right over the Gulf Stream.

A Tropical Storm Watch is in effect for the central SC coast, and a TS Warning has been issued for the northern SC coast and nearly all of the NC coast.  A long-range radar loop showing the convection in the inner core and the banding can be found at http://weather.noaa.gov/radar/loop/DS.p20-r/si.kclx.shtml
The pause in forward motion will probably result in a smaller chance of landfall; the approaching trough will pick the storm up and take it northeast away from the coast, but it will be close.

Elsewhere, there's a strong tropical wave tracking across the deep tropics.  It exited the African coast on July 28 and is now at about 42W, moving W at 20 kts.  There is an embedded 1014mb Low associated with the wave at about 11N.  This will be watched for further organization in the coming days.

Please visit my tropical Atlantic headquarters.